VL53L1X - i2c consumption

RE: VL53L1X - i2c consumption

mike_actinius — Tue, 01 Mar 2022 11:32:28 GMT

Hi Alskandar,

So there are actually pull up resistors on the breakout board. That's actually where the leakage is coming from. These resistors have a marking 05C which is 11kOhms, so that accounts exactly for the amount that you see when you push XSHUT to GND!

Just remove these 2 resistors and you should be fine 🙂

BR,

Mike

RE: VL53L1X - i2c consumption

Alskandar — Tue, 01 Mar 2022 11:14:40 GMT

Hi Mike,

I tested sensor by itself (juste VCC & GND connected).

At 3,3V, it gives 12,5uA

At 2,8V, it gives 10,5uA

So i have a little more than in datasheet (5uA at 2,8V).

Unfortunately , i don't have the design plans for this sensor.

Here is a photo, there seems to be resistors (350 Ohms, i think, on GPIO1 & XSHUT) but i don't know what the others are.

RE: VL53L1X - i2c consumption

mike_actinius — Fri, 25 Feb 2022 10:30:44 GMT

Hi Alskandar,

Since you see this regardless whether I2C is connected perhaps something in your firmware "misbehaves" when the I2C to the sensor is lost (when XSHUT is low I2C is disabled on the sensor anyway). As a sanity check I would check the sensor separately, without any other board connected and that should yield 5-7 uA. If that is indeed the case, then you should check your firmware on how it handles sleep mode when losing connection to the sensor.

Are you absolutely positive that there are no components on the breakout board? A ~10k pull-up resistor on XSHUT could easily justify this amount of current drawn when setting XSHUT to low

BR,

Mike

RE: VL53L1X - i2c consumption

Alskandar — Fri, 25 Feb 2022 09:27:18 GMT

Hi Mike, yes that's it.

I made a bridge between XSHUT and GND.

I think this is the same as if i directly connect XSHUT to 0V, right ?

And i get 340uA.

RE: VL53L1X - i2c consumption

mike_actinius — Wed, 23 Feb 2022 11:54:03 GMT

Hi Alskandar,

In the case of XSHUT connected to GND, you measured 340uA? Is that correct or is it a typo?

BR,

Mike

RE: VL53L1X - i2c consumption

Alskandar — Fri, 18 Feb 2022 16:02:02 GMT

Hi Mike,

Yes i agree for i2c, it's just an information like what to connect or not VCC / GND, as long as i2c is connected, there are these 10uA.

I did the tests:

always 45uA (for VCC + XSHUT without or with i2c)
340uA (for GND + XSHUT without or with i2c)

if it is the hardware shutdown current, this consumption should disappear once the operation is carried out, right ?

Even after 30sec, still nothing.

RE: VL53L1X - i2c consumption

mike_actinius — Thu, 17 Feb 2022 11:56:54 GMT

Hi Alskandar,

In general the I2C should never be connected without the IC being properly connected on VCC and GND. Some (most?) times the ICs get backpowered from the I2C/UART/etc lines when not properly connected to VCC+GND.

From what I see there are no pull-ups on the breakout board, so that takes away the possibility of leakage from them.

Here is what I would do to pinpoint the source:

- Connect GND + VCC, tie XSHUT TO VCC, leave I2C and GPIO1 unconnected -> measure the current

- Tie the XSHUT line to GND -> measure the current

- Connect the I2C lines with short wires -> measure the current

That should give us where the current difference is coming from.

The datasheet specifies that hardware shutdown current draw can be up to 7uA, and that's for 2.8V VDD, so in my opinion most of what you see is just that. But anyway, the above should give more info.

BR,

Mike

RE: VL53L1X - i2c consumption

Alskandar — Thu, 17 Feb 2022 10:16:16 GMT

Hi mike_actinius

No, i don't use a breakout board.

Not in the sense with additional features.

This one:

It seems, as Øyvind assumed, that it comes from the leakage current at in off mode or 0V (or just i2c plugged in without 3V3 and GND).

I am looking to see if there is a simple solution to put in place to "scrape" these uAs and lower consumption.

RE: VL53L1X - i2c consumption

mike_actinius — Thu, 17 Feb 2022 01:11:14 GMT

Hi Alskandar,

Are you using the VL53L1X with a breakout board? If so, which one and what is on it?

PS the FTDI is completely unrelated to this and it anyway does not draw any current when the USB is unconnected. You schematic Alskandar seems fine and VBAT is indeed the right pin to connect the Otii.

BR,

Mike

RE: VL53L1X - i2c consumption

ivnn — Wed, 16 Feb 2022 10:11:34 GMT

I meant you should desolder it

RE: VL53L1X - i2c consumption

Alskandar — Wed, 16 Feb 2022 09:31:43 GMT

The Otii Arc power the board in 3.6V (on Vbat) at the same times it takes the measurement.
For UART, in my prj.conf i make CONGIG_SERIAL=n, same for spm.conf.
Otherwise the consumption increases by 600uA.

RE: VL53L1X - i2c consumption

ivnn — Tue, 15 Feb 2022 18:46:58 GMT

Onboard, FTDI UART Bridge could take this current. Try to add power directly to 3.3V pin

RE: VL53L1X - i2c consumption

Alskandar — Tue, 15 Feb 2022 18:15:22 GMT

Here is the diagram of Icarus board with VL53L1X sensor (connected in i2c on 26 & 27, 3V3 & GND).

Without sensor connected, i have a consumption near 33uA

With sensor connected, all connected (GND, 3V3 & i2c) or even with just i2c (without 3V3 & GND), i have a consumption near 45uA

RE: VL53L1X - i2c consumption

ivnn — Tue, 15 Feb 2022 17:10:24 GMT

Pls, provide a simplified schematic of your setup this might help us to guide you

RE: VL53L1X - i2c consumption

Alskandar — Tue, 15 Feb 2022 17:03:15 GMT

Hi,

Yes i saw it too but i don't know how to use this information.

Should i mount an auxiliary system with a resistor to block state ?

For current measurement, i use an Otii Arc (on Vbat & GND with Icarus Board) (like SMU mode with nRF9160-DK).

Thanks

RE: VL53L1X - i2c consumption

Øyvind — Mon, 14 Feb 2022 14:55:19 GMT

Hello,

Looking at the datasheet of the sensor itself, it looks like the sensor has a leakage current of 10µA when AVDD is 0V. How are you measuring the current consumption?

Kind regards,
Øyvind

RE: VL53L1X - i2c consumption

Alskandar — Sun, 13 Feb 2022 21:59:31 GMT

Hi,
I'm with an nRF9160.
I tried like this, without success.

That is to say that the ports are at 0V but no reduction in consumption. 
Worse when I reactivate the port, it rises above 1.5mA.

pins_vl53L1X = device_get_binding("GPIO_0");
gpio_pin_configure(pins_vl53L1X, 26, GPIO_OUTPUT);
gpio_pin_configure(pins_vl53L1X, 27, GPIO_OUTPUT);
gpio_pin_set(pins_vl53L1X, 26, 0);
gpio_pin_set(pins_vl53L1X, 27, 0);

RE: VL53L1X - i2c consumption

ivnn — Fri, 11 Feb 2022 23:46:32 GMT

Hi,
try to configure gpio pins to tri-state, which could be done with nrf_gpio_cfg_default(pin)